x86, uv: add early detection of UV system types

Portions of the ACPI code needs to know if a system is a UV system prior
to genapic initialization. This patch adds a call early_acpi_boot_init()
so that the apic type is discovered earlier.

V2 of the patch adding fixes from Yinghai Lu.
Much cleaner and smaller.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 1b4763e..51c0a2f 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -138,7 +138,7 @@
 		return;
 	}
 
-	if (is_uv_system())
+	if (get_uv_system_type() >= UV_X2APIC)
 		apic_id = (pa->apic_id << 8) | pa->local_sapic_eid;
 	else
 		apic_id = pa->apic_id;